Merge pull request #3909 from edx/feanil/update-default-vagrantfile

Upgrade default vagrant file to one that runs elasticsearch 1.5

vagrant/release/devstack/Vagrantfile

@@ -63,7 +63,7 @@ openedx_releases = {
   # Cypress is deprecated and unsupported
   # Birch is deprecated and unsupported
 }
-openedx_releases.default = "ficus-devstack-2017-02-07"
+openedx_releases.default = "devstack-periodic-2017-06-12"
 
 openedx_release = ENV['OPENEDX_RELEASE']
 boxname = ENV['OPENEDX_BOXNAME']